<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script>
    /**
     *  根据消费金额显示 vip 等级
     *  0 - 100     VIP1
     *  100 - 500   VIP2
     *  500 - 2000  VIP3
     */
    // let jine = 2000;
    let jine = 3000;
    // let jine = 0;

    //判断 jine 变量的值
    if(jine <= 0){
      alert('欢迎 欢迎');
    }else if(jine > 0 && jine <= 100){
      alert('欢迎 VIP1');
    }else if(jine > 100 && jine <= 500){
      alert('欢迎 VIP2');
    }else if(jine > 500 && jine <= 2000){
      alert("欢迎 VIP3");
    }else{
      //其他的情况
      alert('欢迎 VIP4');
    }


  </script>
</body>
</html>